I. Field of the Invention
The present invention relates to wireless telephone systems. More particularly, the present invention relates to a method and apparatus for paging a concentrated subscriber system for wireless local loop that allows for simplified construction of the concentrated subscriber system while maintaining maximum compatibility with prior art cellular telephone systems.
II. Description of the Related Art
Wire based or wire line telephone systems are the traditional method of providing non-mobile telephone service. Wire based telephone systems are well suited for this task because they provide high quality connections at a low operating cost and can accommodate increased demand for telephone service by the introduction of new telephone wires into the existing network. A disadvantage of wire base telephone systems is the substantial infrastructure and capital necessary for their implementation. These requirements can make wire based telephone systems uneconomical in areas that are remote or less populated, or in less developed areas where the required capital is unavailable. The result is that these less populated and remote areas often lack adequate telephone service which is detrimental to the to the economic well being of the people who live in those areas. Also, the time necessary to put the required infrastructure in place makes wire based telephone systems less desirable in areas where new telephone service must be provided quickly.
Wireless cellular telephone systems require substantially less capital and infrastructure than wire based telephone systems and therefore provide a possible alternative for providing primary telephone service. The degree to which cellular telephone systems can provide primary telephone service is limited, however, by their higher operating cost as compared to wire based telephone system which translates into a higher usage cost for the cellular telephone system subscriber. This higher usage cost limits the number of subscribers that can afford to use a cellular telephone system as their primary telephone service provider within a given area and therefore reduces the number of markets in which the use of cellular telephone systems is economical.
A cellular telephone system that provides simple telephone service at a reduced cost when compared to previous cellular telephone systems is described in co-pending U.S. patent application Ser. No. 08/384,291 entitled "Concentrated Subscriber System for Wireless Local Loop" filed concurrently herewith on Jan. 10, 1994 and assigned to the assignee of the present invention. The concentrated subscriber system described in that application includes a set of subscriber units that share a control and interface system which in the preferred embodiment incorporates code division multiple access (CDMA) digital technology because of its high bandwidth efficiency and high quality communication capability. Such a system reduces the cost of cellular telephone service incurred by each cellular telephone subscriber by spreading the cost of the control and interface system over a larger number of subscribers. This increases the number of markets in which it is economical to use cellular telephone systems as a primary provider of telephone service and therefore increases overall access to telephone service.
Many cellular telephone systems, including those using the preferred CDMA technology, page or "ring" the various subscriber units that are part of the cellular telephone system using a unique paging method for each subscriber unit or sub-set of subscriber units that are part of the cellular telephone system. This is done so that page messages can be directed to single one or a sub-set of the total number of subscriber units thereby simplifying the page monitoring process for each subscriber unit. In the case of the concentrated subscriber system, however, using multiple paging methods for paging makes the control and interface system described more complex. This is because the control and interface system must be capable of interacting in accordance with multiple different paging methods in order to monitor for paging messages directed to any one of the multiple subscriber units that are part of the concentrated subscriber system. Higher complexity is contrary the goal of the concentrated subscriber system, however, which is providing basic cellular telephone service at a reduced cost. Therefore, the use of the standard method of paging a subscriber unit in combination with a concentrated subscriber system cellular telephone system is undesirable.